Ladle preparation



1970 e. H. DICKERHOOF, JR 3,487,843

LADLE PREPARATION Filed Dec. 19, 1967 Geoeec- D/CKEQHOOF- BY Wm 84 INVENTOR.

Ma ATTORNEYS.

United States Patent O 3,487,843 LADLE PREPARATION George H. Dickerhoof, Jr., Canton, Ohio, assignor to Republic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey Filed Dec. 19, 1967, Ser. No. 691,786 Int. Cl. B2261 41/10; B65d 47/30; G01m 3/00 US. Cl. 137-11 12 Claims ABSTRACT OF THE DISCLOSURE In the preparation of a ladle for receiving molten metal, the ladle having a nozzle and a stopper, a method of determining if the stopper is properly seated wherein a flowable material having the characteristic of vaporizing upon contact with the molten metal is placed around the seatengaging portion of the stopper.

BACKGROUND OF THE INVENTION This invention relates generally to the preparation of a ladle for receiving molten metal, and more specifically to a method of determining whether the stopper of a ladle is properly seated against the nozzle.

The customary procedure of preparing a ladle to receive a heat of molten metal involves adjusting the ladle valve so that it is fully closed. In the case of a bottompour ladle having a nozzle and a stopper, the common practice has been to utilize sand as a means of determining Whether or not the head of the stopper is properly seated against the nozzle. After the nozzle and the stopper have been set in place, the sand is poured around the stopper head and any leakage of the sand'through the nozzle indicates that the stopper has not been correctly positioned.

The practice of using sand has a serious disadvantage in that the sand remains in the ladle when it is filled with metal and normally forms inclusions in the first ingot that is poured. Because of the sand inclusions, it is a conventional procedure to discard the first ingot when pouring certain types of metals, such as aircraft and bearing grade steels. Rather than pour a complete first ingot, one-half of an ingot is poured in many instances and then discarded. In either case a substantial loss of metal is incurred because of inclusions resulting from the use of sand or the like when seating the stopper.

SUMMARY OF THE INVENTION The present invention contemplates the use of a material which has the characteristic of vaporizing upon the contact with the molten metal as a means of determining whether the stopper of the ladle valve is properly seated. A suitable, volatile material, preferably in particulate or granular form, is placed around the stopper head after it has been initially set in place against the nozzle seat. As in the case of the conventionally used sand, any flow of the particulate material through the nozzle indicates that the stopper head is not properly seated and that the stopper must be adjusted. When the heat is thereafter tapped into the ladle, the material vaporizes and therefore will not come out with the molten metal when the first ingot is poured.

Since the material is vaporized when the heat is tapped into the ladle, the method of this invention obviates the necessity of discarding the first ingot or partial ingot that is poured because of inclusions.

Accordingly, an object of the invention is to provide a method which utilizes a material that will not form inclusions in the poured ingots as a means for determing Whether the value of a ladle is fully closed.

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A more specific object of the invention is to provide a new method for determining if the stopper of a ladle is properly seated characterized by the use of a flowable material which vaporizes upon contact with the molten metal tapped into the ladle.

Other objects, advantages and a fuller understanding of the invention will be had from the following detailed disclosure and from the accompanying drawing.

DESCRIPTION OF THE DRAWING FIGURE 1 is a fragmentary, vertical cross-sectional view of a bottom-pour ladle; and

FIGURE 2 is an enlarged view of a portion of the ladle shown in FIGURE 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, there is shown a portion of a conventional bottom-pour ladle 10 having a refractory lining 11. The ladle 10 is provided with the usual stopper 12 which acts as a valve in cooperation with a nozzle 13 to control the flow of molten metal from the ladle.

The stopper 12 includes a metal stopper rod 15 which is protected by surrounding, refractory stopper rod sleeves 16. A refractory stopper head 17 is secured to the lower end of the rod 15 for cooperation with the nozzle 13. The ladle rigging for raising and lowering the stopper rod 15 is mounted on the outside of the ladle. As shown, the rigging includes a carrier or gooseneck 18 which is secured to the upper end of the stopper rod 15 and to the upper end of a slide 19. The slide 19 is movable through a barrel 20 by actuation of a suitable lever assembly 21 at the lower end of the slide. The ladle rigging also includes a wheel and screw assembly 22 which can be used to adjust the stopper 12 laterally relative to the nozzle 13 in order to properly seat the stopper head 17 against the nozzle.

As is conventional, the nozzle 13 is inserted in a nozzle-retaining plate 27. The upper surface 28 of the nozzle defines a seat for the stopper head 17. A well 29 which may be made of brick, clay or loam is formed above the nozzle for the purpose of guiding the stopper head 17 into engagement with the seat 28.

Prior to tapping a heat of metal into the ladle, the nozzle 13 is set in place and the stopper 12 is moved to engage the head 17 against the seat 28. As is shown in FIGURE 2, a quantity of material 31) is then poured around the stopper head 17 to determine if it has been properly seated so as to fully close the nozzle. Any leakage of the material 30 through the nozzle indicates that the head has not been properly seated and the stopper 12 is then adjusted until this has been accomplished.

In accordance with this invention, the fioWable material 30 has the characteristic of vaporizing upon contact with the molten metal tapped into the ladle. The preferred materials are particulate or granular substances. Sodium chloride or common salt, for example, is ideally suited for purposes of the present invention and has been used successfully to detect improper seating of the stopper head. Sodium chloride has a boiling point of approxi mately 2714 F. which is less than the tapping temperature of a steel heat which ranges in the neighborhood of 3000 F. depending upon the particular composition and grade of the steel. It has been discovered that the vaporized sodium chloride does not attack the stopper and ladle materials and has no deleterious effect on the steel melt. Other suitable materials which will vaporize upon contact with the molten metal without effecting either the melt or the stopper and ladle include organic compounds such as sugar or the like; and granulated synthetic resins including Teflon resins, such as polytetrafluoroethylene,

and organic chloride compounds, such as polyvinyl chloride and the like.

Since the material 30 vaporizes upon contact with the molten metal tapped into the ladle, it does not form contaminations in the melt. Thus, the first ingot poured from the ladle will not have the inclusions resulting from the prior art practice of using sand to determine if the ladle stopper is properly seated.

Many modifications and variations of the invention will be apparent to those skilled in the art in the light of the foregoing detailed disclosure.

What is claimed is:

1. In the preparation of a ladle for receiving molten metal, the ladle having a discharge valve including a seat and a stopper, a method of determining if the valve is closed comprising the steps of placing around the seat engaging portion of the stopper a flowable material and detecting any leakage of said material through the valve, said flowable material having the characteristic of vaporizing upon contact with the molten metal tapped into the ladle.

2. A method as claimed in claim 1 wherein the material is a particulate substance.

3. A method as claimed in claim 2 wherein said material is sodium chloride.

4. A method as claimed in claim 2 wherein said material is an organic compound.

5. A method as claimed in claim 4 wherein said material is sugar.

6. A method as claimed in claim 4 wherein said material is a granular synthetic resin.

7. In the preparation of a bottom-pour ladle for receiving molten metal, the ladle having a nozzle and a stopper including a head which is engageable against the seat of the nozzle to block the flow of metal through the nozzle, a method comprising the steps of engaging the stopper head against the nozzle seat, placing a flowable granular material around the stopper head, and determining from any leakage of said material through the nozzle whether the head is properly seated, said material having the characteristic of vaporizing upon contact with the molten metal tapped into the ladle.

8. A method as claimed in claim 7 wherein said material is sodium chloride.

9. A method as claimed in claim 7 wherein said material is sugar.

10. A method as claimed in claim 7 wherein said material is Teflon.

11. A method as claimed in claim 7 wherein said material is an organic chloride based substance.

12. A method as claimed in claim 11 wherein said material is polyvinyl chloride.

References Cited UNITED STATES PATENTS 668,242 2/1901 Watkins 25l368 XR 1,439,522 12/1922 Howard 25l368 XR 2,200,310 5/1940 .Thayer et al. 7346 XR 2,296,059 9/1942 Sage 25 1368 XR 2,310,290 2/1943 Honiss l37-1 XR 2,599,832 6/1952 Hodge 254368 XR 2,660,560 11/1953 Pickard 137-1 2,934,943 5/1960 Carrie 73-46 3,028,874 4/1962 Burkett 25l368 XR SAMUEL SCOTT, Primary Examiner US. Cl. X.R. 

